HIV drugs 'cocktail' slashes mortality, prolongs life: study

The vast majority of people who take the anti-HIV drug "cocktail" can expect to survive at least a decade, one of the largest assessments of this key medication regime said.

The evaluation, published in next Saturday's issue of the British medical weekly The Lancet, encompasses data from Europe, Australia and Canada of 7,740 individuals with the AIDS virus.

They were enrolled into the study before the advent of highly active antiretroviral therapy (HAART) in 1997; during 1997-98, when HAART became available in limited quantities; and 1999-2001, when it became widely accessible in those countries.

Pre-1997, people with HIV aged 15 to 24 years would survive, on average, for 12.5 years after they became infected.

By comparison, among people aged 45-54, the survivability was much lower - they lived on average for just 7.9 years after infection.

After 1997, though, HAART started to make a dramatic impact, the study shows.

In its first year of introduction, when about one in five HIV patients in the study had access to the drugs, death rates were reduced by 50 percent compared with pre-1997 levels.

Mortality in 2001, when 57 per cent of the study's patients had access to the drugs, fell a remarkable 80 per cent compared with before 1997.

Because HAART was introduced only six years ago and most of the people who are taking it are still alive, it is impossible to give a projection as to their longevity, research leader Kholoud Porter, of Britain's MRC Clinical Trials Unit, said.

But she said in all the age categories, from 15 years to 64 years, the survivability is likely to be a decade.

"Ten years after infection, 90 percent of people with HIV who took HAART were still alive, regardless of how old they were," she said.

"It has raised survivability expectations for everyone, regardless of age."

She said there was no sure reason why the age difference in survivability had ironed out between the pre- and post-HAART thresholds.

She speculated that older patients were relatively disciplined about taking their medications, and this had helped their chances.

HAART comprises a regime of three anti-retroviral drugs that inhibit the reproduction of the human immunodeficiency virus (HIV).

In many cases, it can reduce HIV loads to below detectable levels.

But it is not a cure and it can have toxic side-effects.

If the drugs are stopped, the virus bounces back and progressively overwhelms and destroys the immune system.

Until recently, the high cost of the drugs has made them accessible only in rich, developed countries.

However, the price has now come down significantly, making it possible to start distributing them in poor African countries that are bearing the brunt of the global HIV/AIDS pandemic.

The study is the latest to confirm the historic impact of HAART in the fight against AIDS.

In September, a Swiss study of mortality rates found that people who respond well to HAART and who do not have hepatitis-C can have a better short-term mortality rate than people who have been successfully treated for cancer.

It said a commonly-imposed bar on life insurance against people with the AIDS virus was unfair and not justified by the facts.

Meanwhile, US researchers have identified a series of proteins that enable HIV to bypass the human body's natural anti-viral defences and multiply, a discovery they say could lead to new treatment drugs for HIV and AIDS.

"We've discovered a new link in the chain that allows the HIV to overcome the cellular resistant factor and to infect human cells," Dr Xiao-Fang Yu, associate professor at Johns Hopkins Bloomberg School of Public Health, wrote in the on-line edition of Science magazine.

"By identifying the proteins involved in this process, we may be able to develop new drugs and therapies for preventing HIV infection," Dr Yu wrote, who headed a research team that identified the proteins through a series of complex laboratory experiments.

The study said the AIDS virus contains a viral infection factor essential to escaping the human body's natural anti-viral agent.

To circumvent this protective agent, HIV acts in conjunction with a group of proteins to modify and disable the anti-viral agent, said the research team.